A telephone conference call is a means by which multiple participants communicate by calling into a conference “bridge,” which is a system that enables all of the call's participants to hear each other. In the prior art, a conference call is arranged for by obtaining, from the conferencing service that provides the bridge, a telephone number and pass code with which to access the bridge. The bridge telephone number and pass code are distributed ahead of time to all of the participants of the call. At the time that the conference call is scheduled to begin, each participant dials into the bridge by using the telephone number and pass code.
The problem with having conference call participants dialing into the bridge is that it takes time for everyone to join the conference, as it is up to each participant to realize that the conference is starting, to find the telephone number and pass code, and to call in. Alternatively, if the conferencing service were to out-dial to the participants, instead of the participants manually dialing in, then the service would have to communicate with one or more of the telecommunications endpoints (e.g., an Internet-protocol telephone, a notebook computer, a personal digital assistant [PDA], a tablet computer, etc.) that belong to each participant. This would be made possible by using the Session Initiation Protocol, or “SIP.”
SIP is a set of standardized communication rules for initiating and maintaining communications for telephony, presence-based systems, instant messaging, and other telecommunications applications. The protocol provides a way to communicate with a group of endpoint devices that are based on a public address. A SIP-based, out-dialing system could derive a set of registered endpoint addresses for each participant from each public address and use those endpoint addresses when attempting to invite each user to a conference call.
The limitation with using SIP for conferencing, however, is that it does not inherently simplify the administration of conference calls prior to the actual call event, in terms of arranging for the call and setting up the resources for the call. For example, adding public addresses to the list of participants can be awkward. In addition, having the conferencing system out-dial to the participants, instead of the other way around, often has to be manually provisioned one participant at a time.
What is needed is a way to improve the arranging for and setting up of a conference call, without some of the disadvantages in the prior art.